Pregnancy and Vaccination, by Dr. Natalie Casaclang (April 2024)

Pregnancy can be a worrying time for new and experienced parents alike. Immediately, expectant parents think about the well-being and health of their child. They are faced with endless choices and decisions about what is best for their baby and it can be difficult to know what to do, whose advice to follow and what is safe.

Fortunately, thanks to scientific studies, stringent approval processes, rigorous safety control systems and decades of data collection, we know a lot about the safety of vaccines during pregnancy.

Three vaccines are recommended during pregnancy: influenza, Covid-19 and pertussis. They are safe and help protect pregnant persons and their unborn baby from infection and serious outcomes due to infection. If you are pregnant or considering becoming pregnant, a pertussis vaccine is particularly important. Over the past year, Manitoba experienced the largest outbreak of the disease since 1995 and pertussis is the second most reported vaccine-preventable disease in Canada.

Pertussis is commonly known as whopping cough because the disease's most noticeable symptom is a cough followed by a `whoop' sound ahead of the next breath. This contagious infection of the lungs and airways makes it difficult for infants and children to eat, drink, or even breathe. Severe infection can lead to pneumonia, brain damage, seizures and death, especially in infants, who are not eligible for their first dose of pertussis vaccine until two months of age.

A pertussis vaccine during pregnancy, called the Tdap vaccine, can help in two important ways. While it is still possible to catch pertussis while pregnant, one dose of Tdap significantly reduces the chance of a stillbirth, a premature birth or low birth weight as a result of the disease. Second, a pertussis vaccine during pregnancy creates antibodies in the expectant individual, which are then passed to the baby in the womb. The baby gains short-term protection against the disease until it can be vaccinated.

The pertussis vaccine is best administered between 27 and 32 weeks of pregnancy and is recommended for every pregnancy, not just a first pregnancy.

If you are pregnant or planning to get pregnant, talk to your health-care provider about getting a pertussis vaccine and help protect your baby. Good information about immunizations, including vaccinations during pregnancy and while breastfeeding, is also available at https://immunize.ca/.

Together, we can all help protect Manitoba's youngest residents.

Dr. Natalie Casaclang, MD, CCFP, FRCPC
Medical Officer of Health
Population and Public Health
Health, Seniors and Long-Term Care